Machine for sharpening gin-saws



(No Model.) I 2 SheetsSheet 1. J. M. BRADLEY. MACHINE FUR SHARPENING GIN No. 595,520. Patented Dec. 14,1897.

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, J. M. BRADLEY. MACHINE FOR SHARPENING GIN SAWS.

No. 595,520; Patented Dec 14,1897.

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UNITED STATES PATENT FFICE.

JAMES M. BRADLEY, OF HILLSIDE TEXAS.

MACHINE FOR SHARPENING GIN-SAWS.

SPECIFICATION forming part of Letters Patent No. 595,520, dated December 14, 1897.

Application filed April 3, 397- To all whom it may concern:

Be it known that I, JAMES M. BRADLEY, a citizen of the United States, residing at Hillside, in the county of McLennan and State of Texas, have invented new and useful Improvements in Machines for Sharpening Gin- Saws, of which the following is aspecification.

This invention relates to machines for sharpening gin-saws, and has for its object to provide an improved machine of the character described wherein the saws may be sharpened without removing them or any other operative part from the gin and wherein the files in sharpening one tooth automaticallyoperate to impart a partial rotation to the saw to bring the next saw-tooth in position to be filed.

It has for its further object to provide the reciprocating file-holders with a longitudinally-yielding pitman, whereby the fileswill act upon each tooth with the same force or power irrespective of the resistance encountered or the power applied for driving the machine,and whereby the files operate to sharpen each tooth alike irrespective of the difference of length of the teeth and regardless of any defects that may exist in the teeth.

Finally, it has for its object to improve and simplify the construction and increase the efficiency of this class of machines generally.

To these ends my invention consists in the features and in the combination, arrangement, or construction of parts hereinafter described, and particularly pointed out in the claims following the description, reference bein g had to the accompanying drawings, forming a part of this specification, wherein Figure 1 is a side elevation of my improved machine. Fig. 2 is a top plan view thereof, and Fig. 3 is a detail view of the slide-bar and file-holders removed from the machine.

Referring to the drawings, the numeral 1 indicates an upright rectangular frame for supporting the driving mechanism of the machine. In one of the uprights 2 of the frame is journaled a shaft 3, on the inner end of which is mounted a crank-wheel 4. On the outer end of the stud-shaft?) is fixed a small pinion 5, which is engaged by a gear-wheel 6, journaled on a stud-shaft 7, fixed in the upright before referred to. The gear or drive wheel 6 is provided with a crank 8, by means Serial No. 631,994. (No model.)

of which said wheel may be rotated by hand to drive the crank-wheel 4.

Fixed to the uprights 2 are two approximately parallel horizontal arms 9, and to said arms intermediate their ends is rigidly fastened a strap or stirrup 10, that operates to maintain the bars 9 the proper distance apart. Aset-screw 11 is tapped through said strap or stirrup and at its upper end engages the under side of one end of a guide-block 12. The guide-block 12 at its other end is fitted on a threaded bolt 13, journaled at its opposite ends in the arms 9, and may be adjusted laterally on the bolt 13 by means of nuts 14, tapped over said bolt and engaging the opposite sides of the guide-block. The guide-block is longitudinally'slotted from end to end, and

fitted and adapted to be reciprocated back and forth therein is a slide-bar 15, the forward end of which is forked or bifurcated, as shown, to form two arms or file-holders 16 and 17. The rear ends of the arms 16 and 17 are flattened to form springs 18, and said arms are crossed one over the other, as shown. The springs 18 yield to permit the holders 16 and hereinafter explained. The free ends of the arms are bent inward toward each other, as at 19, and said bent ends are provided with small perforations, in which are inserted the ends of files 20. The opposite ends of the files are clamped to the holders by bolts and nuts 21.

The slide-bar is actuated by a pitman driven by the crank-Wheel 4 and constructed in the following manner: The pitman 22 is j ournaled at one end on a wrist-pin 23, eccentrically fixed on the crank-wheel 4, and at its other end is loosely pivoted to the rear end of the slide-bar 15-by a pin 24, passing through the end of the pitman and through an elongated slot 25, formed in the end of the slide-bar. The pitman is threaded intermediate its ends, as at 26, and tapped over said threaded portion is a nut 27. A coiled spring 28 is arranged .17 to cross each other and operate to throw on the pitman and at one end bears against the nut 27 and at its other end bears against the end of the slide-bar. The pitman may thus have a limited yielding movement relative to the slide-bar for the purpose hereinaftersetforth, and such movement may be regulated by adjusting the tension of the coiled spring by means of the nut 27.

Arranged in vertically-elongated slots 29, formed in the forward ends of the arms 9, is a threaded rod or shaft 30, on which is rotatably arranged a sleeve or roller 31. Nuts 32 are arranged on the outer ends of the shaft 30, by means of which said shaft may be vertically adjusted in the elongated slots. The file-holders 1G and 17 are adapted to engage the roller 31 during a portion of their reciprocation, and their simultaneous downward and forward thrustis limited thereby. Curved or hooked arms 33 are mounted on the rod or shaft 30 between the opposite ends of the roller 31 and the arms 9 and are adapted to be hooked over the arbor of the gin-saws and support the machine in operative position.

By adjusting the rod or shaft 30 in the elongated slots 29 the hooked arms or hangers 33 are adjusted vertically for the purpose hereinafter explained.

The operation of my improved machine is as follows: Vhen itis desired to sharpen the saws, the latter need not be removed from the gin, it being only necessary to rest the frame 1 on a bench or other suitable support in front of the gin and then raise the usual breast of the gin, after which the hooked arms 33 may be arranged on the arbor of the gang of saws. The ends of the holders are then sprung apart and caused to engage the opposite sides of one of the saws, in which position the two files 2O engage the edges of two teeth of the saw. The drive-wheel 6 being rotated, the slide-bar 15 is reciprocated back and forth in guide-block 12. As the files engage the teeth of the saw at a point below the axis of the latter, the saw is rotated by the files as the latter advance, and as the saw rotates the files and their holders are forced downward by the rotating teeth with which they are in engagement (the springs 18 yielding vertically to permit such downward movement) until the holders strike against the roller 31, which acts as a stop and arrests the downward movement of the holders. When the holders strike the roller 31, the files are prevented from moving in a downward direction, and therefore they are unable to further rotate the saw,and hence as the files continue to move forward they move tangentially relatively to the saw and act on the teeth with a filing movement and sharpen the same. In this forward movement of the files to sharpen the teeth the springs 18 yield laterally to permit the file-holders to slip one across the other to change the point of contact between the holders to accommodate the advancing movement of the files. At the end of the forward movement of the holders the driving mechanism operates to retract them, and in their rearward movement the files slip over the teeth without moving the saw, as the pressure of the files on the saw is not sufiicient in such rearward movement to turn the gang of saws in their bearings and against the gin-driving mechanism. As the files are retractcd the tendency of the springs 18 is to raise the holders, and hence the files bear against the under side of the teeth above them and round the rear edges of the teeth off. At or near the end of the .rearward movement of the holders the files disengage the teeth previously operated upon, and the springs 18 then immediately act to throw the holders and files upward into position to engage the next succeeding teeth and to throw the holders above and out of contact with the roller 31. As the files are again thrust forward they engage the teeth next above those previously sharpened and give the saw another partial rotation until the holders again strike the roller 31, when the rotation of the saw ceases and the files operate to sharpen the teeth in the manner before described.

From the foregoing it will be understood that in the forward movement of the files they first operate to partially rotate the saw to bring the teeth into proper position for engagement by the files on their next succeeding advance, and on their continued advance they operate to file the teeth.

By raising or lowering the guide-block 12 by means of the screw 11 it will be evident that the holders will be adjusted from or toward the roller 31, and hence the movement communicated to the saw by the files will be regulated. For example, if the guide-block be raised the holders will be moved farther away from the roller 31, and hence the files will have an increased forward movement before the holders strike the roller, whereby the saw will be rotated a greater distance at each reciprocation of the files. In this manner the files may be caused to feed the saw so that the teeth will be acted on successively, or so that the alternate teeth only will be acted on, or the device can be adjusted to act upon different-sized saws or saws having different-sized teeth or teeth of different pitch.

By adjusting the roller 31 in its elongated bearings the height at which the hangers support the arms 9 is regulated, and hence the point on the periphery of the saws at which the files engage it is determined, and in this manner the filing action of the files upon the teeth may be adjusted or varied.

In practice many of the teeth in each saw become broken or stripped off, forming gaps or what is known in the art as 'low places, and when newteeth are cut in these low places said new teeth are manifestly not in the same circular plane as the other teeth, but are nearer the center of the saw. In sharpening IIO saws having these low places it will be evident that unless especial provision be made the teeth in the low places will not be acted on by the files or will be acted on but slightly, either resulting in the failure of the files to feed or rotate the saw or in the feed being insufficient and irregular, and the imperfect sharpening of the teeth in the low places. In

order to cause the files to act on all the teeth alike, I make the pitman 22 yielding in the manner described, whereby when the files are Operating on regular teeth the spring 28 will be under considerable tension, but when the files encounter short teeth or teeth in low places the spring will expand and give an increased throw to the files, thus causing the latter to enter between the short or low teeth and sharpen them along their entire length and also feed the saw the regular and desired distance for engaging the next teeth.

The machine above described is entirely automatic in its action, the files operating to sharpen the teeth and also operating to automatically feed or rotate the saw the proper distance to present new teeth to be operated on at every reciprocation of the files and without any manipulation or attention on the part of the attendant. It will also be understood that the machine will act precisely the same upon both regular and irregular teeth and that the saws may be sharpened without removing them from the gin or disturbing any of the parts of the gin or their adjustment.

Having described my invention, what I claim is v 1. In a machine for sharpening gin-saws, the combination with a frame, of a reciprocating slide-bar, two crossed and vertically and laterally yielding file-holders carriedby the slide-bar, files carried by said holders, and a stop arranged in the forward end of said frame and operating to arrest the downward thrust of the file-holders, substantially as de-' scribed.

2. In a machine for sharpening gin-saws, the combination with a frame, of a reciprocating slide-bar, two crossed and verticallyyielding file-holders carried by the slide-bar, files carried by said holders, and a verticallyadjustable stop arranged in the forward end of said frame and operating to arrest the downward thrust of the file-holders, substantially as described.

3. In a machine for sharpening gin-saws, the combination with a frame, of a reciprocating slide-bar, two crossed and vertically and laterally yielding file-holders carried by the slide-bar, files carried by the holders, and a vertically-adjustable roller arranged in the forward end of said frame and operating to arrest the downward thrust of the file-holders, substantially as described.

4.. In a machine for sharpening gin saws, the combination with a frame having two horizontal and approximately parallel arms, a guide-block secured between said arms, a

slide-bar fitted to reciprocate in said guideblock and provided at its forward end with two crossed and vertically and laterally yielding file-holders, files arranged in said holders, driving mechanism for reciprocating the slidebar, and hangers attached to the forward end of the frame for suspending the same from the arbor of the saws to be sharpened, substantially as described.

5. In a machine for sharpening gin-saws, the combination with a frame having two horizontal and approximately parallel arms, a guide-block adj ustably secured between said arms, a slide-bar fitted to reciprocate in said guide-block and provided at its forward end with two crossed and vertically and laterally yielding file-holders, files arranged in said holders, driving mechanism for reciprocating the slide bar, and a verticallyadjustable roller arranged in the forward end of the said arms beneath the file-holders and operating to limit the downward thrust of the file-holders, substantially as described.

6. In a machine for sharpening gin-saws, the combination with a frame, of a reciprocating slide-bar, two crossed and vertically and laterally yielding file-holders carried by said slide-bar, files carried by said holders, a stop arranged in the forward end of said frame and operating to arrest the downward thrust of the file-holders, a pitman yieldingly connected to the slide-bar, and mechanism for driving the pitman, substantially as described.

7. In a machine for sharpening gin-saws, the combination with a frame 'having two horizontal and approximately parallel arms, a guide-block secured between said arms, a slide-bar fitted to reciprocate in said guideblock and provided at its forward end with two crossed and vertically and laterally yielding file-holders, files arranged in said holders, a driven crank-wheel, and a yielding pitman connecting said crank-wheel and slide-bar, substantially as described.

8. In a machine for sharpening gin-saws, the combination with a frame having two horizontal and approximately parallel arms, a guide-block secured between said arms, a slide-bar fitted to reciprocate in said guideblock and provided at its forward end with two crossed and vertically and laterally yielding file-holders, files arranged in said holders, a driven crank-wheel, a pitman eccentrically connected at one end to said crank-wheel and loosely journaled in an elongated slot in the rear end of the slide-bar, a coiled spring surrounding said pitman and an adjusting-nut threaded on the pitman, said spring bearing at one end against said nut and at its other end against the rear end of the pitman, substantially as described.

9. In a machine for sharpening gin-saws, the combination with a guide-block, of a slidebar fitted to reciprocate therein and bifurcated or forkedat its forward end to form two In testimony whereof I have hereunto set my hand in presence of two subscribing wit- 1o nesses.

JAMES M. BRADLEY.

Witnesses:

J. W. FROST,- T. J. PAMIM. 

